clause/2 only works for dynamic predicates. > On 27 Aug 2017, at 06:14, Curtis Hoffmann <[email protected]> wrote: > > I have the Clocksin and Mellish Programming in Prolog book, and I'm trying to > get past all the errors. > One of the programming examples is for a replacement of listing (p. 182). > > list1(X) :- > clause(X, Y), > output_clause(X, Y), write('.'), nl, fail. > list1(X). > > output_clause(X, true) :- !, write(X). > output_clause(X, Y) :- write((X :- Y)). > > If I type the question ?- list1(list1). > I get no response back. Am I doing something wrong, or is there something > about clause that I don't understand? > I tried checking the archives and didn't see this question asked before. > > Thank you in advance. > Curtis > > _______________________________________________ > Users-prolog mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/users-prolog
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